What is the dosing for Irbesartan (Angiotensin II receptor antagonist)?

From the Guidelines

Irbesartan should be started at 150 mg once daily for adults with hypertension, with the option to increase to 300 mg once daily if blood pressure control is inadequate, as recommended by the most recent guidelines 1. The dosing of irbesartan is crucial in managing hypertension and diabetic nephropathy.

• The starting dose is typically 150 mg once daily, which can be increased to 300 mg once daily if needed.
• For patients with volume depletion, a lower starting dose of 75 mg may be considered.
• In patients with diabetic nephropathy in type 2 diabetes, the target dose is 300 mg once daily. Some key points to consider when prescribing irbesartan include:
• No dosage adjustment is needed for mild to moderate hepatic impairment or for elderly patients, though careful monitoring is advised.
• In patients with renal impairment, no initial dosage adjustment is necessary, but monitoring of kidney function and potassium levels is important.
• Irbesartan can be taken with or without food at the same time each day to maintain consistent blood levels. The mechanism of action of irbesartan involves blocking angiotensin II receptors, relaxing blood vessels, and lowering blood pressure.
• Patients should be aware that full therapeutic effects may take 2-4 weeks to develop, and regular blood pressure monitoring is recommended, especially when initiating therapy or adjusting doses, as supported by the guidelines 1. The most recent guidelines from 2020 and 2022 support the use of irbesartan in the management of hypertension and heart failure, with a target dose of 300 mg once daily 1.
• The guidelines emphasize the importance of achieving target doses of guideline-directed medical therapies, including irbesartan, to improve outcomes in patients with heart failure.
• The 2022 guideline specifically recommends a target dose of 300 mg once daily for irbesartan, which is consistent with the dosing recommendations for adults with hypertension 1.

From the FDA Drug Label

2.2 Hypertension The recommended initial dose of irbesartan tablets is 150 mg once daily. The dosage can be increased to a maximum dose of 300 mg once daily as needed to control blood pressure [see Clinical Studies (14.1)]. 2.3 Nephropathy in Type 2 Diabetic Patients The recommended dose is 300 mg once daily [see Clinical Studies (14.2)]. 2.4 Dose Adjustment in Volume- and Salt-Depleted Patients The recommended initial dose is 75 mg once daily in patients with depletion of intravascular volume or salt (e.g., patients treated vigorously with diuretics or on hemodialysis) [see Warnings and Precautions (5.2)]. The dosing for irbesartan is as follows:

• Hypertension: initial dose of 150 mg once daily, with a maximum dose of 300 mg once daily as needed to control blood pressure 2.
• Nephropathy in Type 2 Diabetic Patients: 300 mg once daily 2.
• Volume- and Salt-Depleted Patients: initial dose of 75 mg once daily 2.

From the Research

Dosing Information for Irbesartan

• The recommended starting dosage of irbesartan is 150 mg once daily, which can be increased to 300 mg 3.
• Irbesartan can be used alone or in combination with other antihypertensive agents, such as hydrochlorothiazide 4.
• In patients with mild-to-moderate hypertension, irbesartan was as effective as enalapril, atenolol, and amlodipine, and more effective than valsartan in terms of absolute reduction in blood pressure and response rates 5.
• The combination of irbesartan with hydrochlorothiazide produced additive effects on blood pressure reduction 5.
• Irbesartan is effective in reducing blood pressure in hypertensive patients with chronic renal disease, with a daily dose of 150-300 mg 6.

Special Considerations

• Irbesartan is well tolerated in hypertensive patients, including those with type 2 diabetes and incipient or overt nephropathy 5.
• The overall incidence of adverse events with irbesartan was similar to that with placebo 5.
• Irbesartan was associated with a lower incidence of cough than enalapril and was not associated with ankle edema or any clinically significant drug interactions 5.
• Dosage adjustments are unnecessary in patients with renal or hepatic disease 3.

Clinical Trials

• In the IRMA 2 trial, the proportion of patients progressing to overt nephropathy was significantly lower for recipients of irbesartan 300 mg once daily than placebo 5.
• In patients with overt nephropathy in the IDNT, irbesartan 300 mg once daily provided significantly greater renoprotection than amlodipine 10 mg once daily or placebo 5.
• Irbesartan exerted a renoprotective effect in hypertensive patients with type 2 diabetes at both the early and later stages of diabetic nephropathy 5.